In the year 2005 , a picture supposedly painted by a famous artist some time after 1715 but before 1765 contains 97.6 percent of its carbon-14 (half-life 5730 years). From this information, could this picture have been painted by this artist? ? Approximately how old is the painting? \( \square \) years

In the year 2005 , a picture supposedly painted by a famous artist some time after 1715 but before 1765 contains 97.6 percent of its carbon-14 (half-life 5730 years). From this information, could this picture have been painted by this artist? ? Approximately how old is the painting? \( \square \) years

SECTION 3: Balance the following chemical reactions. a. \( \frac{\mathrm{Zn}}{\mathrm{Zinc}+\underset{\text { Hydrochloric Acid }}{\mathrm{HCl}} \rightarrow \underset{\mathrm{Zinc}}{\mathrm{ZnCl}}+\frac{\mathrm{H}_{2}}{\text { Chloride }}+\text { Hydrogen gas }} \)

How many mols are there in each of the following samples? (convert grams to mols) a. 42 grams of the radioactive isotope Carbon-14

\( \begin{array}{l}\text { Gas nitrogen dioksida }\left(\mathrm{NO}_{2}\right) \text { dapat membentuk gas } \\ \text { dinitrogen tetroksida }\left(\mathrm{N}_{2} \mathrm{O}_{4}\right) \text { dalam kesetimbangan } \\ \text { sebagai berikut: } \\ 2 \mathrm{NO}_{2}(\mathrm{~g})=\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \\ \text { Jika pada suatu suhu diketahui konsentrasi } \mathrm{NO}_{2}= \\ 0,2 \mathrm{M} \text { dan } \mathrm{N}_{2} \mathrm{O}_{4}=0,5 \mathrm{M} \text {, tentukan nilai konstanta } \\ \text { kesetimbangan } \mathrm{Kc} \text { untuk reaksi tersebut. }\end{array} \).

4. How many atoms are found in a 15.3 g sample of bismuth? A. \( 1.26 \times 10^{26} \) atoms B. \( 4.41 \times 10^{22} \) atoms C. \( 6.02 \times 10^{23} \) atoms D. \( 9.21 \times 10^{24} \) atoms